Display device and method for manufacturing the same

ABSTRACT

A display device includes a substrate including a display area and a non-display area, and a common electrode line at the non-display area of the substrate. The common electrode line may include a line unit and a plurality of protrusions that protrude from the line unit in a direction opposite from the display area.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to and the benefit of Korean PatentApplication No. 10-2014-0099254, filed in the Korean IntellectualProperty Office on Aug. 1, 2014, the entire content of which isincorporated herein by reference.

BACKGROUND

1. Field

Embodiments of the present invention relate to a display deviceincluding a common electrode line having a protrusion, and a method formanufacturing the same.

2. Description of the Related Art

Flat panel displays such as liquid crystal displays (LCDs) and organiclight-emitting diode (OLED) displays include a pair of electric fieldgenerating electrodes and an electro-optical active layer interposedtherebetween. A liquid crystal layer is included as the electro-opticalactive layer in LCDs and an organic emission layer is included as theelectro-optical active layer in OLED displays.

At least one pixel electrode and at least one counter electrode are usedto drive an electro-optical active layer. The pixel electrodes arecategorized according to a pixel (e.g., correspond to a respectivepixel) and the counter electrodes face the pixel electrodes. The counterelectrodes can be replaced with common electrodes that are provided ordisposed for all pixels.

A common electrode line is used to provide the common electrode withpower. The common electrode line is usually located or disposed outsideof a display unit where a pixel is located or disposed and it is made ofa metal having low resistance in order to reduce or prevent IR-drop(e.g., voltage drop).

A patterning process is repeatedly performed in a manufacturing processof a display device, however, which results in damage to the commonelectrode line.

It is to be understood that this background section is intended toprovide useful background for understanding the subject matter disclosedherein and as such, the background section may include ideas, conceptsor recognitions that were not part of what was known or appreciated bythose skilled in the pertinent art prior to the corresponding effectivefiling dates of the subject matter disclosed herein.

SUMMARY

Aspects of embodiments of the present invention are directed toward adisplay device including a common electrode line having a protrusion.

Further, aspects of embodiments of the present invention are directedtoward a method for manufacturing a display device including a commonelectrode line having a protrusion.

According to an embodiment of the present invention, a display deviceincludes a substrate including a display area and a non-display area,and a common electrode line in the non-display area of the substrate.The common electrode line may include a line unit and a plurality ofprotrusions that protrude from the line unit in a direction oppositefrom the display area.

The common electrode line may include a metal.

The display area may include a thin film transistor including a gateelectrode, a semiconductive layer, a source electrode, and a drainelectrode, and the common electrode line may include substantially thesame material as the source and drain electrodes.

The plurality of protrusions may be spaced apart from each other by aset distance.

The plurality of protrusions may be spaced apart from each other bydifferent distances.

Each of the plurality of protrusions may have a set length and thelength may be larger than the distance between the adjacent protrusions.

The length may be in a range of 2 μm to 2000 μm.

The protrusion may have a polygonal or semicircular shape.

The display area may include a display element including a pixelelectrode on the substrate, a light emission layer on the pixelelectrode, and a common electrode on the light emission layer. Thecommon electrode may be coupled to the common electrode line.

The display device may further include a common electrode couplingportion coupled to the common electrode line.

The common electrode coupling portion may include substantially the samematerial as the pixel electrode.

The display device may further include a pixel defining layer on thesubstrate to define a pixel area. The pixel electrode and the lightemission layer may be in the pixel area.

According to another embodiment of the present invention, a method formanufacturing a display device includes forming a display area and anon-display area on a substrate, and forming a common electrode line inthe non-display area on the substrate. The common electrode line mayinclude a line unit and a plurality of protrusions that protrude fromthe line unit in a direction opposite from the display area.

The forming of the display area may include forming a thin filmtransistor on the substrate, and the forming of the thin film transistormay include forming a semiconductive layer, forming a gate electrodethat overlaps at least a portion of the semiconductive layer, andforming a source electrode coupled to the semiconductive layer and adrain electrode spaced apart from the source electrode and coupled tothe semiconductive layer. The forming of the source electrode and thedrain electrode may be performed utilizing substantially the sameprocess as the forming of the common electrode line.

The forming of the display area may include forming one or more displayelements. The forming of the one or more display elements may includeforming a pixel electrode on the substrate, forming a light emissionlayer on the pixel electrode, and forming a common electrode on thelight emission layer. The common electrode may be coupled to the commonelectrode line.

The forming of the pixel electrode may further include forming a commonelectrode coupling portion coupled to the common electrode line.

The method may further include forming a pixel defining layer after theforming of the pixel electrode.

The plurality of protrusions may be spaced apart from each other by aset distance.

The plurality of protrusions may be spaced apart from each other bydifferent distances.

The protrusion may have a polygonal or semicircular shape.

Each of the plurality of protrusions may have a set length and thelength may be larger than the distance between the adjacent protrusions.

The length may be in a range of 2 μm to 2000 μm.

According to embodiments of the present invention, a display deviceincludes a common electrode line having a protrusion. Accordingly, whena layer is formed in a manufacturing process of a display device, alayer-forming material may be evenly or substantially evenly applied toform a uniform or substantially uniform layer.

Further, according to embodiments of the present invention, a displaydevice is manufactured to include a common electrode line having aprotrusion.

The foregoing summary is illustrative only and is not intended to be inany way limiting. In addition to the illustrative aspects, embodiments,and features described above, further aspects, embodiments, and featureswill become apparent by reference to the drawings and the followingdetailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features and other enhancements ofembodiments of the present invention will be more clearly understoodfrom the following detailed description when considered together withthe accompanying drawings, in which:

FIG. 1 is a plan view illustrating a display device according to a firstembodiment of the present invention;

FIG. 2 is an enlarged partial view of part “A” of FIG. 1;

FIG. 3 is a cross-sectional view taken along the line I-I′ in FIG. 2;

FIG. 4 is another example of an enlarged partial view of part “A” ofFIG. 1;

FIG. 5 is an equivalent circuit diagram of a pixel illustrated in FIG.4;

FIGS. 6A to 6D are partial plan views illustrating common electrodelines of display devices according to the first embodiment to a fourthembodiment of the present invention;

FIG. 7 is a cross-sectional view illustrating a display device accordingto a fifth embodiment of the present invention;

FIGS. 8A to 8H are cross-sectional views illustrating sequentialmanufacturing processes of the display device according to the firstembodiment of the present invention;

FIGS. 9A and 9B are cross-sectional views illustrating a commonelectrode line;

FIG. 10 is a plan view illustrating a mother glass for manufacturing aplurality of display devices; and

FIG. 11 is a cross-sectional view illustrating application of an organicmaterial for forming a pixel defining layer.

DETAILED DESCRIPTION

Aspects of embodiments of the present invention will be described withreference to embodiments illustrated in the accompanying drawings.However, the embodiments disclosed in the drawings and the detaileddescription are not intended to limit the scope of the presentinvention.

The accompanying drawings are selected only for illustrative purposesfor embodiments of the present invention. Each element and its shape inthe drawings may be schematically or exaggeratedly illustrated to helpwith understanding embodiments of the invention. Some elements providedfor a commercial embodiment may not be illustrated or may be omitted inthe drawings or the description as those elements should be apparent toone of ordinary skill in the art. The drawings should be construed tohelp the understanding of the invention. Like reference numerals mayrefer to like elements in the specification.

In the specification, when a first element is referred to as being“coupled” or “connected” to a second element, the first element may bedirectly connected to the second element or indirectly connected to thesecond element with one or more intervening elements interposedtherebetween. The terms “comprises,” “comprising,” “includes,” and/or“including,” when used in this specification, may specify the presenceof the stated features, integers, acts, operations, elements, and/orcomponents, but do not preclude the presence or addition of one or moreother features, integers, acts, operations, elements, and/or components.

It will be understood that when an element is referred to as being “on”,“over”, “disposed on”, “disposed over”, “deposited on”, or “depositedover” another element, it can be directly on or over the other elementor indirectly on or over the other element with one or more interveningelements interposed therebetween. Expressions such as “at least one of,”when preceding a list of elements, modify the entire list of elementsand do not modify the individual elements of the list. Further, the useof “may” when describing embodiments of the present invention refers to“one or more embodiments of the present invention.”

Hereinafter, a first embodiment of the present invention will bedescribed with reference to FIGS. 1 to 3.

FIG. 1 is a plan view illustrating a display device according to thefirst embodiment of the present invention. FIG. 2 is an enlarged partialview of part “A” of FIG. 1. FIG. 3 is a cross-sectional view taken alongthe line I-I′ in FIG. 2.

As illustrated in FIG. 1, an organic light emitting diode (OLED) display100 according to the first embodiment includes a substrate 110 having adisplay area 101 and a non-display area 102. The present disclosure,however, is not limited to OLED displays.

The display area 101 of the substrate 110 may include a plurality ofpixels so as to display an image.

A common electrode line 230 may be disposed in the non-display area 102.The common electrode line 230 may be spaced apart from the display area101 and may be located or disposed along an edge of the display area101. The common electrode line 230 may have a protrusion.

Further, a sealing area 220 may be located or disposed more outwardsthan the common electrode line 230.

Referring to FIGS. 2 and 3, the OLED display 100 according to the firstembodiment includes a plurality of pixels that are disposed in thedisplay area 101 and that include a switching thin film transistor (TFT)10, a driving TFT 20, a capacitor 80, and an organic light emittingdiode (OLED) 210. Herein, the term “pixel” refers to the smallest unitfor displaying an image. The OLED display 100 displays an imageutilizing a plurality of pixels.

Although FIG. 2 illustrates an OLED display with a 2Tr-1 Cap structure,which includes two TFTs 10 and 20 (e.g., a switching TFT 10 and adriving TFT 20) and a capacitor 80 in one pixel, embodiments of thepresent invention are not limited thereto. For example, the OLED displayaccording to one embodiment may include three or more TFTs and/or two ormore capacitors in one pixel, and may further include conductive lines.The OLED display according to one embodiment may have many differentstructures.

The OLED display 100 may further include a gate line 151 on thesubstrate 110, and a data line 171 and power line 172 which areinsulated from and intersect (cross) the gate line 151. One pixel may bedefined by the gate line 151, the data line 171, and the power line 172,but it may be differently defined. For example, the pixel may be definedby a black matrix or a pixel defining layer (PDL).

The substrate 110 may include or be an insulating substrate made ofglass, quartz, ceramic, plastic, and/or the like, but embodiments of thepresent invention are not limited thereto. The substrate 110 may includeor be a metal substrate made of stainless steel, etc., or the substrate110 may include or be made of any other suitable material available inthe art of display devices.

A buffer layer 120 may be disposed on the substrate 110. The bufferlayer 120 may reduce or prevent infiltration of undesirable elementssuch as impurities and moisture and may provide a planar surface. Thebuffer layer 120 may include or be made of a suitable material forplanarizing and/or preventing or reducing infiltration. For example, thebuffer layer 120 may include one or more of silicon nitride (SiN_(x)),silicon oxide (SiO₂), or silicon oxynitride (SiO_(x)N_(y), e.g.,Si₂N₂O). In an implementation, the buffer layer 120 may be omitteddepending on the kind and process condition of the substrate 110.

Switching and driving semiconductive layers 131 and 132 (e.g., aswitching semiconductive layer 131 and a driving semiconductive layer132) may be disposed on the buffer layer 120. The switching and drivingsemiconductive layers 131 and 132 may include or be made of one or moreof, e.g., polycrystalline silicon, amorphous silicon, or an oxidesemiconductor such as Indium Gallium Zinc Oxide (IGZO) and Indium ZincTin Oxide (IZTO). For example, in the case of the driving semiconductivelayer 132 illustrated in FIG. 3 including or being made ofpolycrystalline silicon, the driving semiconductive layer 132 mayinclude a channel area 135 that is not doped with impurities, and p+doped source and drain areas 136 and 137 on respective sides of thechannel area 135. In this case, p-type impurities such as boron B may beused as dopant ions. For example, B₂H₆ may be used. Such impurities mayvary depending on the kind of the TFTs. According to the firstembodiment of the present invention, a PMOS-structured TFT using thep-type impurities is utilized as the driving TFT 20, but embodiments ofthe present invention are not limited thereto. For example, anNMOS-structured or CMOS-structured TFT may be used as the driving TFT20.

A gate insulating layer 140 may be disposed on the switching and drivingsemiconductive layers 131 and 132. The gate insulating layer 140 mayinclude one or more of, e.g., tetraethyl orthosilicate (TEOS), siliconnitride (SiN_(x), where 0<x<4/3), or silicon oxide (SiO₂). In animplementation, the gate insulating layer 140 may have a double layerstructure in which a silicon nitride layer having a thickness of about40 nm and a TEOS layer having a thickness of about 80 nm aresequentially laminated.

A gate wire that includes gate electrodes 152 and 155 (e.g., a switchinggate electrode 152 and a driving gate electrode 155) may be disposed onthe gate insulating layer 140. The gate wire may further include a gateline 151, a first capacitor plate 158, and other conductive lines. Thegate electrodes 152 and 155 may be disposed to overlap at least part ofthe semiconductive layers 131 and 132, e.g., to overlap the channelarea. The gate electrodes 152 and 155 may prevent the channel area frombeing doped with impurities (or reduce such doping) when the source anddrain areas 136 and 137 of the semiconductive layers 131 and 132 aredoped with the impurities in the process of forming the semiconductivelayers 131 and 132.

The gate electrodes 152 and 155 and the first capacitor plate 158 may bedisposed on the same layer and may include or be made of substantiallythe same metal material. For example, the gate electrodes 152 and 155and the first capacitor plate 158 may include at least one selected frommolybdenum (Mo), chromium (Cr), and tungsten (W).

An interlayer insulating layer 160 configured to cover the gateelectrodes 152 and 155 may be disposed on the gate insulating layer 140.The interlayer insulating layer 160 may include or be made of tetraethylorthosilicate (TEOS), silicon nitride (SiN_(x)), or silicon oxide(SiO_(x), where 0<x≤2), similarly to the gate insulating layer 140, butembodiments of the present invention are not limited thereto.

A data wire including source electrodes 173 and 176 (e.g., a switchingsource electrode 173 and a driving source electrode 176) and drainelectrodes 174 and 177 (e.g., a switching drain electrode 174 and adriving drain electrode 177) may be disposed on the interlayerinsulating layer 160. The data wire may further include a data line 171,a power line 172, a second capacitor plate 178, and other conductivelines. The source electrode 176 and the drain electrode 177 may berespectively coupled to the source area 136 and the drain area 137 ofthe semiconductive layer 132 through contact openings (e.g., holes).

Thus, the switching TFT 10 may include the switching semiconductivelayer 131, the switching gate electrode 152, the switching sourceelectrode 173, and the switching drain electrode 174, and the drivingTFT 20 may include the driving semiconductive layer 132, the drivinggate electrode 155, the driving source electrode 176, and the drivingdrain electrode 177. The configurations of the TFTs 10 and 20 are notlimited to the above-described embodiment and may vary according toother configurations that should be apparent to those of ordinary skillin the art.

The capacitor 80 may include the first capacitor plate 158 and thesecond capacitor plate 178 with the interlayer insulating layer 160interposed therebetween.

The switching TFT 10 may function as a switching device that selects apixel to emit light. The switching gate electrode 152 may be coupled tothe gate line 151. The switching source electrode 173 may be coupled tothe data line 171. The switching drain electrode 174 may be spaced apartfrom the switching source electrode 173 and may be coupled to the firstcapacitor plate 158.

The driving TFT 20 may apply a driving power to a pixel electrode 211 toenable a light emission layer 212 of the OLED 210 in a selected pixel toemit light. The driving gate electrode 155 may be coupled to the firstcapacitor plate 158. The driving source electrode 176 and the secondcapacitor plate 178 may be coupled to the power line 172. The drivingdrain electrode 177 may be coupled to the pixel electrode 211 of theOLED 210 through a contact hole.

The switching TFT 10 may be operated by a gate voltage applied to thegate line 151, and may function to transmit a data voltage applied tothe data line 171 to the driving TFT 20. A voltage equivalent to adifferential between a common voltage applied to the driving TFT 20 fromthe power line 172 and the data voltage transmitted from the switchingTFT 10 may be stored in the capacitor 80. A current that corresponds tothe voltage stored in the capacitor 80 may flow to the OLED 210 throughthe driving TFT 20 so that the OLED 210 may emit light.

On the interlayer insulating layer 160 of the non-display area 102, thecommon electrode line 230 may be located or disposed more inward thanthe sealing area 220. The common electrode line 230 may include or bemade of the same or substantially the same material as the sourceelectrodes 173 and 176 and the drain electrodes 174 and 177.

The source electrodes 173 and 176, the drain electrodes 174 and 177, andthe common electrode line 230 may include or be made of a metalmaterial. Examples of the metal material may include molybdenum (Mo),chromium (Cr), tungsten (W), aluminum (Al), and/or copper (Cu) and themetals may be used alone or in combination with each other. The sourceelectrodes 173 and 176, the drain electrodes 174 and 177, and the commonelectrode line 230 may have a single layer structure or a multilayerstructure.

As illustrated in FIG. 2, the common electrode line 230 may include aline unit 235 and a protrusion 236.

A planarization layer 180 may be disposed on the interlayer insulatinglayer 160 and may be configured to cover the data wire (171, 172, 173,174, 176, 177, and 178). The planarization layer 180 may serve toplanarize a surface of the OLED 210 that is disposed on theplanarization layer 180 by eliminating or reducing steps (e.g., defects)so as to increase light emission efficiency of the OLED 210. Theplanarization layer 180 may have a pixel contact opening (e.g., hole)through which part of the drain electrode 177 is exposed.

The planarization layer 180 may include or be made of at least oneselected from a polyacrylate resin, an epoxy resin, a phenolic resin, apolyamide resin, a polyimide resin, an unsaturated polyester resin, apolyphenylenether resin, a polyphenylene sulfide resin, andbenzocyclobutene (BCB).

The pixel electrode 211 of the OLED 210 may be disposed on theplanarization layer 180. The pixel electrode 211 may be coupled to thedrain electrode 177 through the contact opening (e.g., hole) of theplanarization layer 180.

The pixel electrode 211 may be any one of the following types or kinds:a transmissive type or kind, a transflective type or kind, and areflective type or kind.

A transparent conductive oxide (TCO) may be used to form the pixelelectrode 211 to be a transmissive electrode. Examples of the TCO mayinclude indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide(ZnO), and/or indium oxide (In₂O₃).

A metal such as magnesium (Mg), silver (Ag), gold (Au), calcium (Ca),lithium (Li), chromium (Cr), aluminum (Al), and/or copper (Cu), and/oralloys thereof may be used to form a transflective electrode and/or areflective electrode. In this case, the transflective electrode and thereflective electrode may have different thicknesses. For example, thetransflective electrode may have a thickness of about 200 nm or less andthe reflective electrode may have a thickness of about 300 nm orgreater. As the thickness of the transflective electrode decreases, bothlight transmittance and resistance may increase. Conversely, as thethickness of the transflective electrode increases, light transmittancemay decrease.

The transflective electrode and/or the reflective electrode may have amultilayer structure that includes a metal layer made of a metal or analloy thereof and a transparent conductive oxide layer laminated on themetal layer.

According to the kind of materials included in the pixel electrode 211and a common electrode 213, the OLED display 100 may be classified intothree types or kinds: a top emission type or kind; a bottom emissiontype or kind; and a dual-side emission type or kind. According to thefirst embodiment, the OLED display 100 is a top emission device. Forexample, the OLED 210 may emit light in a direction of the commonelectrode 213 so as to display an image. In order to improve lightemission efficiency of the top emission OLED display 100, the pixelelectrode 211 may be a reflective electrode. Examples of the reflectiveelectrode may include an electrode having a structure in which atransparent conductive oxide layer made of ITO is laminated on a metallayer including or made of silver (Ag). The reflective electrode mayalso have a triple-layered structure in which silver (Ag), ITO, andsilver (Ag) are sequentially laminated.

In the meantime, a common electrode coupling portion 231 may be disposedon the planarization layer 180 of the non-display area 102. The commonelectrode coupling portion 231 may extend from an upper portion of theplanarization layer 180 to the common electrode line 230 so as to allowthe common electrode line 230 to have an enlarged contact area. Thecommon electrode coupling portion 231 may have the same or substantiallythe same composition and configuration as the pixel electrode 211 andalso may be formed by the same or substantially the same process as thepixel electrode 211.

A pixel defining layer (PDL) 190 may be disposed on the planarizationlayer 180 and may have an opening through which at least part of thepixel electrode 211 is exposed. The pixel electrode 211 may be disposedin a pixel area defined by the PDL 190. In this case, the commonelectrode coupling portion 231 may be partially covered by the PDL 190and another part of the common electrode coupling portion 231 may beexposed.

The PDL 190 may include or be made of a polyacrylate resin, a polyimideresin, and/or the like.

The light emission layer 212 may be disposed on the pixel electrode 211in the pixel area and the common electrode 213 may be disposed on thePDL 190 and the light emission layer 212. The common electrode 213 maybe in contact (e.g., direct contact) with the common electrode couplingportion 231, and thus, the common electrode 213 may be electricallycoupled or connected to the common electrode line 230.

The light emission layer 212 may include a low molecular weight organicmaterial or a high molecular weight organic material. At least oneselected from a hole injection layer (HIL) and a hole transport layer(HTL) may be disposed between the pixel electrode 211 and the lightemission layer 212, and at least one selected from an electron transportlayer (ETL) and an electron injection layer (EIL) may be disposedbetween the light emission layer 212 and the common electrode 213.

The common electrode 213 may be formed as a transflective layer. Thetransflective layer used as the common electrode 213 may include or bemade of at least one metal including magnesium (Mg), silver (Ag),calcium (Ca), lithium (Li), chromium (Cr), aluminum (Al) and/or copper(Cu). The common electrode 213 may have a multilayer structure thatincludes a metal layer including at least one of magnesium (Mg), silver(Ag), calcium (Ca), lithium (Li), chromium (Cr), aluminum (Al) and/orcopper (Cu), and a transparent conductive oxide (TCO) layer laminated onthe metal layer.

As described above, the OLED 210 may include the pixel electrode 211,the light emission layer 212 on the pixel electrode 211, and the commonelectrode 213 on the light emission layer 212. Herein, the pixelelectrode 211 may serve as an anode, which may be a hole injectionelectrode, and the common electrode 213 may serve as a cathode, whichmay be an electron injection electrode. However, embodiments of thepresent invention are not limited thereto, and thus, the pixel electrode211 may be a cathode and the common electrode 213 may be an anodeaccording to a driving method of the OLED display 100.

A sealing member 250 may be disposed on a sealing layer 225 so as tocover the driving TFT 20 and the OLED 210. A transparent insulatingsubstrate including or made of glass or plastic may be utilized as thesealing member 250.

In further detail, the sealing member 250 may face the substrate 110 byway of the sealing layer 225 that is disposed in the sealing area 220 onthe substrate 110.

The sealing member 250 may be spaced apart from the substrate 110 by thesealing layer 225 in the sealing area 220. The sealing layer 225 mayinclude or be made of, for example, sealants and/or frits.

The first embodiment has been described hereinabove with reference toFIGS. 1 to 3, but embodiments of the present invention are not limitedthereto.

In one embodiment, a thin film encapsulation layer in which organic andinorganic layers are alternately laminated may be disposed on the OLED210. In this case, the sealing member 250 and the sealing layer 225 maybe omitted. Further, many different conductive lines, which extend fromthe display area 101 to the non-display area 102, may be insulatedlydisposed between the sealing layer 225 and the substrate 110 so as toprovide signals and/or power.

Hereinafter, another example of a pixel configuration of the displaydevice according to the first embodiment will be described withreference to FIGS. 4 and 5.

In detail, FIG. 4 is another example of an enlarged partial view of part“A” of FIG. 1 and shows a layout of another implementation of a pixelincluded in the OLED display 100 according to the first embodiment.

FIG. 4 illustrates three pixels. FIG. 5 is an equivalent circuit diagramof one of the pixels illustrated in FIG. 4.

Each pixel illustrated in FIG. 4 may include a driving TFT T1, aswitching TFT T2, one or more capacitors C1 and C2, a scan line SCAN[n],a data line DATA[m], a first power line ELVDD, a second power lineELVSS, and an OLED.

The pixel may also include a further scan line SCAN[n-1], emissioncontrol line EM[n], initialization voltage line Vint, and TFTs T3, T4,T5, and T6 including a compensation TFT T3. Initialization voltage VINtransmitted through the initialization voltage line Vint may initializethe driving TFT T1.

The switching TFT T2 may be switch-operated according to scan signalstransmitted through the scan line SCAN[n]. For example, a gate electrodeof the switching TFT T2 may be coupled or connected to the scan lineSCAN[n]. A source electrode of the switching TFT T2 may be coupled orconnected to the data line DATA[m]. The scan line SCAN[n] and the dataline DATA[m] may be located or disposed in respective directionsintersecting (crossing) each other. A drain electrode of the switchingTFT T2 may be electrically coupled or connected to a source electrode ofthe driving TFT T1 and the first power line ELVDD.

The driving TFT T1 may receive data signals according to a switchingoperation of the switching TFT T2 so as to transmit a driving current tothe OLED.

A gate electrode of the driving TFT T1 may be coupled or connected toone electrode of the first capacitor C1. The other electrode of thefirst capacitor C1 may be coupled or connected to the first power lineELVDD.

The first power line ELVDD may be located or disposed parallel orsubstantially parallel to the data line DATA[m]. A drain electrode ofthe driving TFT T1 may be electrically coupled or connected to the anode211 of the OLED. The second power line ELVSS may be coupled or connectedto the cathode 213 of the OLED. Therefore, the OLED may emit light byreceiving the driving current from the driving TFT T1.

The OLED may include the anode 211 that injects holes, the cathode 213that injects electrons, and the light emission layer 212 between theanode 211 and the cathode 213.

Hereinafter, an operating process for the pixel illustrated in FIG. 4will be described in more detail with reference to FIG. 5.

First, while the TFT T4 is in the ON state according to scan signalstransmitted through the scan line SCAN[n-1], the initialization voltageVIN may be supplied to an end of the first capacitor C1 and the gateelectrode of the driving TFT T1.

Next, the switching TFT T2 and the compensation TFT T3 may be turned onaccording to scan signals transmitted through the scan line SCAN[n].While the switching TFT T2 and the compensation TFT T3 are in the ONstate, a data voltage transmitted through the data line DATA[m] may betransmitted to the source electrode of the driving TFT T1, and thedriving TFT T1 may be diode-connected or diode-coupled.

Then, a voltage obtained by subtracting a threshold voltage of thedriving TFT T1 from the data voltage may be applied to the gateelectrode and the source electrode of the driving TFT T1.

Next, the TFTs T5 and T6 may be turned on by emission control signalstransmitted through the emission control line EM[n], and a voltage ofthe gate electrode of the driving TFT T1 may be boosted by an increaseof the scan signals transmitted through the scan line SCAN[n].

While the two TFTs T5 and T6 are in the ON state, a voltage of the firstpower line ELVDD may be supplied to the source electrode of the drivingTFT T1, and a driving current according to a gate-source voltagedifference may flow to the driving TFT T1. The driving current may betransmitted to the anode of the OLED through the turned-on TFT T6.

Hereinafter, configurations of the common electrode line 230 will bedescribed in further detail with reference to FIGS. 6A to 6D.

FIGS. 6A to 6D are partial plan views illustrating common electrodelines of display devices according to the first embodiment to a fourthembodiment of the present invention.

The common electrode line 230 may include a line unit 235 continuouslylocated or disposed outside the display area along the display area anda protrusion 236 protruding from the line unit 235 towards the sealingarea 220.

The line unit 235 may be in contact (e.g., direct contact) with thecommon electrode coupling portion 231. An end portion of the line unit235, which is located towards the display area 101, may be covered andprotected by the planarization layer. In some embodiments, an endportion of the line unit 235, which is located towards the sealing area220, may be exposed for a predetermined or set period of time in theprocess of manufacturing a display device and the protrusion 236 may beformed in the exposed region.

In more detail, FIG. 6A is an enlarged plan view of the common electrodeline 230 of the OLED display 100 according to the first embodiment andthe common electrode coupling portion 231 coupled to the commonelectrode line 230. FIGS. 6B to 6D are enlarged plan views of the commonelectrode lines 230 of OLED displays according to the second throughfourth embodiments, respectively, and the common electrode couplingportions 231 coupled to the common electrode lines 230.

As illustrated in FIG. 6A, the common electrode line 230 may include theline unit 235 and a plurality of protrusions 236 that protrude from theline unit 235 in the opposite direction of the display area (e.g., in adirection away from the display area). Referring to FIG. 6A, theplurality of protrusions 236 may be spaced apart from each other by apredetermined or set distance.

Each protrusion 236 may have a length I and a width w. The length I maybe equal to a distance that protrudes from the line unit 235 in theopposite direction of the display area (e.g., the direction away fromthe display area), and the width w may be perpendicular or substantiallyperpendicular to the length I. A distance d between the protrusions 236may be equal to a distance between the neighboring protrusions.

The length l and width w of the protrusion 236 and the distance dbetween the neighboring protrusions 236 may be identical to each otheror different from each other.

The common electrode line 230 illustrated in FIG. 6A may have theplurality of protrusions 236 that have the predetermined or set length land width w and the predetermined or set distance d therebetween.

An OLED display 200 may include a common electrode line 230 illustratedin FIG. 6B, which may have a plurality of protrusions 236 that havedifferent lengths l from each other. For example, as shown in FIG. 6B, afirst set of protrusions 236 may have lengths that are different fromlengths of a second set of protrusions 236. In some embodiments, thelengths of the first set may be the same as one another, and the lengthsof the second set may be the same as one another.

An OLED display 300 may include a common electrode line 230 illustratedin FIG. 6C, which may have a plurality of protrusions 236 that havedifferent lengths I and widths w from each other and irregular (e.g.,non-predetermined) distances d therebetween. For example, as shown inFIG. 6C, a first set of protrusions 236 may have lengths and widths thatare different from lengths and widths of a second set of protrusions236. In some embodiments, the lengths of the first set may be the sameas one another, the widths of the first may be the same as one another,the lengths of the second set may be the same as one another, and thewidths of the second set may be the same as one another.

An OLED display 400 may include a common electrode line 230 illustratedin FIG. 6D, which may have a protrusion 236 that is semicircular inshape.

In a display device according to embodiments of the present invention,the configurations of the common electrode line 230 are not limited toFIGS. 6A to 6D, but can be changed in various ways. The shapes of theprotrusion 236 are not limited to a quadrilateral or semicircle as shownin FIGS. 6A to 6D, but can be a polygon such as triangle, pentagon, andthe like.

The common electrode line 230 may be patterned into a predetermined orset shape in the process of forming the data wire including the sourceand drain electrodes 176 and 177. The length l of one protrusion 236 maybe larger than the distance d between the one protrusion 236 and anadjacent protrusion 236, and then layer-forming materials may easilyflow out of or around the protrusions 236 due to an attractive forceexerted between the layer-forming materials applied to the oneprotrusion 236 and applied to the adjacent protrusion 236, respectively.

The length l of the protrusion 236 may vary depending on the size of adisplay device and the width of the common electrode line 230.Therefore, the length l of the protrusion 236 may be in a range of 2 μmto 2000 μm, but the length l is not limited thereto. In the case of alarge display device, the length l of the protrusion 236 may be greaterthan 2000 μm. Further, the distance d between the protrusions 236 may bein a range of 1 μm to 1000 μm, but the distance d is not limitedthereto.

Hereinafter, a fifth embodiment of the present invention will bedescribed with reference to FIG. 7, and in order to avoid repetitions,only differences between the above-described embodiments and the fifthembodiment will be described without repeating the descriptions of thecomponents of the first embodiment.

Referring to FIG. 7, an OLED display 500 may include a common electrodecoupling portion 231 and a pixel defining layer (PDL) 190 that overlapsthe common electrode line 230. The PDL 190 may have a contact opening(e.g., hole) 199 in a region corresponding to the common electrodecoupling portion 231. The common electrode 213 and the common electrodecoupling portion 231 may be coupled to each other through the contactopening (e.g., hole) 199, and accordingly power supplied to the commonelectrode line 230 may be transmitted to the common electrode 213 (e.g.,through the contact opening or hole 199). In this case, the PDL 190 mayor may not overlap the protrusion 236 of the common electrode line 230.

Hereinafter, a method for manufacturing the OLED display 100 accordingto the first embodiment will be described with reference to FIGS. 8A to8H.

As illustrated in FIG. 8A, a buffer layer 120 may be formed on thesubstrate 110, which includes or is made of glass or plastic, asemiconductive layer 132 may be formed on the buffer layer 120, a gateinsulating layer 140 may be formed on the semiconductive layer 132, agate wire including a gate electrode 155 and a first capacitor plate 158may be formed on the gate insulating layer 140, and a photosensitivematerial may be applied to the gate wire in order to form a materiallayer 161 for an interlayer insulating layer.

Next, as illustrated in FIG. 8B, the material layer 161 for aninterlayer insulating layer and the gate insulating layer 140 may bepartially removed to form a source contact opening (e.g., hole) 166 anda drain contact opening (e.g., hole) 167 that allows parts of source anddrain areas of the semiconductive layer 132 to be exposed.

Next, as illustrated in FIG. 8C, a source electrode 176 and a drainelectrode 177 that are coupled to the semiconductive layer 132 throughthe source contact opening (e.g., hole) 166 and the drain contactopening (e.g., hole) 167, respectively, may be formed, and a data line171, a second capacitor plate 178, and a power line 172 may also beformed such that a data wire may be formed. In addition, the commonelectrode line 230 may be formed on an interlayer insulating layer 160of the non-display area 102.

The common electrode line 230 may include or be formed of the same orsubstantially the same material as that of the source and drainelectrodes 176 and 177 by the same or substantially the same process asthe source and drain electrodes 176 and 177. In this case, the commonelectrode line 230 may be patterned to include a line unit 235 and aprotrusion 236.

Next, as illustrated in FIG. 8D, a planarization layer 180 having apixel contact opening (e.g., hole) 182 may be formed. In order to formthe planarization layer 180, a planarization layer-forming material maybe applied to the data wire and the common electrode line 230 so as toform a material layer for a planarization layer, and thenphotolithography may be performed utilizing a pattern mask (e.g., toform the pixel contact opening or hole 182). Examples of theplanarization layer-forming photosensitive material may include siliconnitride (SiN_(x)) or silicon oxide (SiO₂), and/or a photosensitive resincomposition.

Next, as illustrated in FIG. 8E, a pixel electrode 211 and a commonelectrode coupling portion 231 coupled to the common electrode line 230may be formed on the planarization layer 180. The pixel electrode 211may be coupled to the drain electrode 177 of a driving TFT 20 throughthe pixel contact opening (e.g., hole) 182. The common electrodecoupling portion 231 may extend to an upper portion of the planarizationlayer 180. The common electrode coupling portion 231 may include or beformed of the same or substantially the same material as the pixelelectrode 211 by the same or substantially the same process as the pixelelectrode 211.

In one embodiment, the pixel electrode 211 and the common electrodecoupling portion 231 may be formed by a method including an act offorming a conductor material layer by forming a metal layer on theplanarization layer 180 and the common electrode line 230 and laminatinga transparent conductive oxide layer on the metal layer and an act ofpatterning the conductor material layer.

The common electrode line 230 may include the line unit 235 and aplurality of protrusions 236 that protrude from the line unit 235 in theopposite direction of the display area (in the direction away from thedisplay area). Each protrusion 236 may have a length l and a width w.The length l may be equal to a distance that protrudes from the lineunit 235 in the opposite direction of the display area, and the width wmay be perpendicular or substantially perpendicular to the length l. Adistance d between the protrusions 236 may be equal to a distancebetween the neighboring protrusions.

The length l and width w of the protrusion 236 and the distance dbetween the neighboring protrusions 236 may be identical to each otheror different from each other.

Next, as illustrated in FIG. 8F, a photosensitive organic material maybe applied to the pixel electrode 211, the common electrode couplingportion 231, the common electrode line 230, and the entire orsubstantially the entire surface of the exposed planarization layer 180so as to form an organic material layer 191 for a pixel defining layer,and then photolithography may be performed utilizing a pattern mask 820.

The pattern mask 820 may include a mask substrate 821 and alight-shielding pattern 822 on the mask substrate 821. An exposed partof the organic material layer 191 for a pixel defining layer may beremoved in a developing process and a non-exposed part thereof may stillremain after the developing process, but the present disclosure is notlimited thereto. For example, in some embodiments, the exposed part mayremain and the non-exposed part may be removed according to the kind ofthe photosensitive organic material.

Examples of the photosensitive organic material may include polyacrylateresins and/or polyimide resins. In order to form the organic materiallayer 191 for a pixel defining layer, a slit nozzle may be used to applythe photosensitive organic material, such as polyacrylate resins and/orpolyimide resins. The common electrode line 230 may include theprotrusion 236. Thus the photosensitive organic material may betemporarily accumulated on the protrusion 236 of the common electrodeline 230, and thereafter it may be combined with the photosensitiveorganic material accumulated on the adjacent protrusion 236 and thecombined photosensitive organic materials may be dispersed into theneighboring sealing area 220, or the like. Therefore, the photosensitiveorganic material may not be accumulated in a single place or location,thereby forming a uniform or substantially uniform organic layer.

Next, as illustrated in FIG. 8G, a pixel defining layer (PDL) 190 havingan opening 195 may be formed through a developing process. The PDL 190may be a stable layer formed utilizing thermal curing or photocuring.The opening 195 of the DL 190, which is formed on the pixel electrode211, may correspond to a pixel area. Further, the common electrodecoupling portion 231 may be partially exposed.

Next, as illustrated in FIG. 8H, a light emission layer 212 may beformed on the pixel electrode 211 that is exposed through the opening195 of the PDL 190, and a common electrode 213 may be formed on thelight emission layer 212 and the PDL 190. The common electrode 213 maybe in contact (e.g., direct contact) with the common electrode couplingportion 231.

Thereafter, a sealing member 250 may be formed on the common electrode213 such that the OLED display 100 as illustrated in FIG. 3 may bemanufactured.

Hereinafter, features of forming the protrusion 236 of the commonelectrode line 230 will be described with reference to FIGS. 9A and 9B.

FIG. 9A is a cross-sectional view illustrating the common electrode line230 on the interlayer insulating layer 160. The common electrode line230 formed with the data wire may have a positive tapered cross-sectionas illustrated in FIG. 9A.

The common electrode line 230 may include or be formed of a metal andthe planarization layer 180 may be formed only on one end portion (e.g.,left side) of the common electrode line 230 (as shown in FIG. 9B).Meanwhile, developing may be performed in the process of forming theplanarization layer 180 after the common electrode line 230 is formed,and developing and etching may be performed in the process of formingthe pixel electrode 211 and the common electrode coupling portion 231 onthe planarization layer 180. While the developing and etching arerepeatedly performed, the exposed end portion (e.g., the right side) ofthe common electrode line 230 is likely to be damaged. As a result, theexposed end portion of the common electrode line 230 may have aninverse-tapered shape 239 as illustrated in FIG. 9B.

In the meantime, in order to form the PDL 190, the photosensitiveorganic material may be applied to the pixel electrode 211 and thecommon electrode line 230. In this case, the photosensitive organicmaterial should not be accumulated in a particular region but shouldflow so as to form the PDL 190 to be smooth and have a uniform orsubstantially uniform thickness. As illustrated in FIG. 10, in anembodiment of a process of manufacturing a plurality of display devicesutilizing one mother glass, the photosensitive organic material appliedto the entire or substantially the entire mother glass 11 should flowuniformly or substantially uniformly on the mother glass 11.

In the case where an end portion of the common electrode line 230 has apositive tapered shape as illustrated in FIG. 9A, the photosensitiveorganic material may easily flow down a slope of the end portion of thecommon electrode line 230. However, when the end portion of the commonelectrode line 230 has an inverse-tapered shape 239, and thus, isdamaged as illustrated in FIG. 9B, the photosensitive organic materialmay not easily flow down the damaged end portion of the common electrodeline 230 and may be accumulated at the end portion of the commonelectrode line 230. Therefore, a step (e.g., a defect) may occur in theorganic material layer for a pixel defining layer.

FIG. 11 is a cross-sectional view illustrating application ofembodiments of a photosensitive organic material for a pixel defininglayer. As illustrated in FIG. 11, when the photosensitive organicmaterial supplied from a nozzle 910 fails to easily flow down an endportion of the common electrode line 230, the photosensitive organicmaterial may be accumulated at the end portion of the common electrodeline 230 and the accumulated photosensitive organic material mayreversely flow toward the display area 101 as shown with arrows. Asdescribed above, when the photosensitive organic material is accumulatedat the end portion of the common electrode line 230, a height of thephotosensitive organic material which should be suitably or desirably h1may become h2 or h3. Until the height of the photosensitive organicmaterial becomes h2 or h3, the photosensitive organic materialaccumulated at the end portion of the common electrode line 230 may notflow to an adjacent region, and then a step (e.g., a defect) may occurin the organic material layer for the pixel defining layer. Therefore,the pixel defining layer may fail to be formed to have a uniform orsubstantially uniform layer thickness. Accordingly, the OLED display 100may have poor quality in light emission.

According to some embodiments of the present invention, when an endportion of the common electrode line 230 includes a protrusion 236, aphotosensitive organic material accumulated on one protrusion 236 may becombined with a photosensitive organic material accumulated on theadjacent protrusion 236 and the combined photosensitive organicmaterials may easily flow, and thus it may be accumulated to have asuitable height at the end portion of the common electrode line 230.Consequently, a pixel defining layer that is smooth and has a uniform orsubstantially uniform thickness may be obtained.

From the foregoing, it will be appreciated that various embodiments ofthe present disclosure have been described herein for purposes ofillustration, and that various modifications may be made withoutdeparting from the scope and spirit of the present disclosure.Accordingly, the various embodiments disclosed herein are not intendedto be limiting, and the invention is intended to cover variousmodifications and equivalent arrangements included within the scope andspirit of the appended claims, and equivalents thereof.

What is claimed is:
 1. A display device comprising: a substratecomprising a display area and a non-display area; a common electrodeline in the non-display area of the substrate; a planarization layer ona part of the common electrode line; and a common electrode couplingportion on the planarization layer and coupled to the common electrodeline, wherein the common electrode line comprises: an electrode lineextending in a first direction parallel to a side of the non-displayarea, the electrode line having first and second sides defining a widthof the electrode line in a second direction perpendicular to the firstdirection, the first side being adjacent to the display area andoverlapping with the planarization layer, the second side being oppositeto the first side and spaced apart from the planarization layer in aplan view; and a plurality of protrusions that protrude from the secondside of the electrode line and are spaced apart from the planarizationlayer and common electrode coupling portion in a plan view, wherein thedisplay area comprises a display element comprising: a pixel electrodeon the planarization layer; a light emission layer on the pixelelectrode; and a common electrode on the light emission layer, thecommon electrode being coupled to the common electrode line.
 2. Thedisplay device of claim 1, wherein the common electrode line comprises ametal.
 3. The display device of claim 1, wherein the display areacomprises a thin film transistor comprising a gate electrode, asemiconductive layer, a source electrode, and a drain electrode, and thecommon electrode line comprises the same as the source and drainelectrodes.
 4. The display device of claim 1, wherein the plurality ofprotrusions are spaced apart from each other by a set distance.
 5. Thedisplay device of claim 1, wherein the plurality of protrusions arespaced apart from each other by different distances.
 6. The displaydevice of claim 1, wherein each of the plurality of protrusions has alength in the second direction and the length is larger than thedistance in the first direction between the adjacent protrusions.
 7. Thedisplay device of claim 6, wherein the length is in a range of 2 μm to2000 μm.
 8. The display device of claim 1, wherein the protrusion has apolygonal or semicircular shape.
 9. The display device of claim 1,wherein the common electrode coupling portion comprises the samematerial as the pixel electrode.
 10. The display device of claim 1,further comprising a pixel defining layer on the substrate to define apixel area, wherein the pixel electrode and the light emission layer arein the pixel area.
 11. The display device of claim 1, wherein a distancebetween the adjacent ones of the plurality of protrusions is in a rangeof 1 μm to 1000 μm.
 12. A method for manufacturing a display device, themethod comprising: forming a display area and a non-display area on asubstrate; forming a common electrode line in the non-display area onthe substrate; forming a planarization layer on a part of the commonelectrode line; and forming a common electrode coupling portion on theplanarization layer and coupled to the common electrode line, whereinthe common electrode line comprises: an electrode line extending in afirst direction along a side of the non-display area, the electrode linehaving a first edge and a second edge defining a width of the electrodeline, the first edge being adjacent to the display area and overlappingwith the planarization layer, the second edge being opposite to thefirst edge and spaced apart from the planarization layer in a plan view;and a plurality of protrusions that protrude from the second edge theelectrode line and are spaced apart from the planarization layer andcommon electrode coupling portion in a plan view, wherein the forming ofthe display area comprises forming one or more display elements, whereinthe forming of the one or more display elements comprises: forming apixel electrode on the planarization layer; forming a light emissionlayer on the pixel electrode; and forming a common electrode on thelight emission layer, the common electrode being coupled to the commonelectrode line.
 13. The method of claim 12, wherein the forming of thedisplay area comprises forming a thin film transistor on the substrate,and the forming of the thin film transistor comprises: forming asemiconductive layer; forming a gate electrode that overlaps at least aportion of the semiconductive layer; and forming a source electrodecoupled to the semiconductive layer and a drain electrode spaced apartfrom the source electrode and coupled to the semiconductive layer,wherein the forming of the source electrode and the drain electrode isperformed utilizing the same process as the forming of the commonelectrode line.
 14. The method of claim 12, further comprising forming apixel defining layer after the forming of the pixel electrode.
 15. Themethod of claim 12, wherein the plurality of protrusions are spacedapart from each other by a set distance.
 16. The method of claim 12,wherein the plurality of protrusions are spaced apart from each other bydifferent distances.
 17. The method of claim 12, wherein the protrusionhas a polygonal or semicircular shape.
 18. The method of claim 12,wherein each of the plurality of protrusions has a length in the seconddirection and the length is larger than a distance in the firstdirection between the adjacent protrusions.
 19. The method of claim 18,wherein the length is in a range of 2 μm to 2000 μm.